Season both sides of fish. Heat a large saute pan, and then add the olive oil. When oil is hot, add mahimahi pieces, skin side down. After 3 minutes, turn strips over and cook for another 3 minutes. Place fish over the Poblano Mashed Potatoes and spoon Tomato-Cumin Relish on top to plate.
Boil potatoes until tender. Rice potatoes and then, with a whisk, incorporate milk and butter. Puree poblano, scallions, cilantro, parsley, spinach and lime juice in a blender. Add mixture to potatoes and combine. Season to taste.
Combine tomatoes, onion, and scallions. Coat with olive oil. Add cumin. Season, to taste.